Device having an electroformed pleated region and method of its manufacture

ABSTRACT

A deflectable, flexible device includes an elongate body, a convoluted tip portion at a distal end of the elongate body, and a lumen to receive one or more wires. The convoluted tip portion includes an electroformed pleated region which is formed by electrodepositing a metal on a mandrel having a pleated region. The convoluted tip portion may be hermetically sealed to permit repeated sterilization. The electroformed pleated region may include one or more fluid emission orifices. The convoluted tip portion extends or bends in response to fluid pressure manipulation, contact with tissue, manipulation with an internal spring or wire, or by a user pushing, pulling, or twisting the catheter directly or via an introducer sheath or the like. The convoluted tip portion may further include an RF ablation element or other energy-driven technique to create continuous linear lesions or a sensing element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. provisionalpatent application No. 61/428,790, filed 30 Dec. 2010, which is herebyincorporated by reference as though fully set forth herein.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The instant disclosure relates to deflectable and steerable elongatedevices, such as medical catheters. In particular, the instantdisclosure relates to a family of such devices having portions formedusing electroforming techniques, including bendable and stretchablepleated or bellows-like regions, partial and entire shaft portions, andthe like.

b. Background Art

Deflectable and steerable elongate devices such as catheters are usedfor an ever-growing number of medical, industrial, and manufacturingprocedures. For example, in the case of the former, catheters are usedfor diagnostic, therapeutic, and ablative procedures, to name just a fewexamples. A catheter can be manipulated through a patient's vasculatureto a portion of targeted tissue or other intended site, for example, asite within or near the patient's heart or other organ or locationwithin a body. A catheter typically carries one or more energy emittingelements (e.g., electrodes, hyperthermic ablation elements, cryogenicelements, etc.), which may be used for tissue ablation, diagnosis, orthe like. Some catheters perform only passive or diagnostic functionssuch as sensing the electrical waveforms of a beating heart.

An important aspect of any catheter procedure is good contact betweenthe catheter and the targeted tissue of an organ or other location inthe body. Accordingly, it is desirable for a catheter to have a flexibletip portion such that the catheter can bend and increase its contactarea to tissue.

BRIEF SUMMARY OF THE INVENTION

It is desirable, therefore, to provide a family of deflectable orsteerable and flexible devices such as medical catheters that bothadvantageously reduce the possibility of tissue perforation and betterconform to tissue due at least in part to specific flexible shaftsegments or other portions (e.g., a flexible tip portion and/or shaft)formed via electroforming techniques alone or in combination with otherfabrication techniques, materials, and components.

It is also desirable to provide a catheter that is readily sterilizablefor multiple uses.

It is also desirable to provide a catheter having a controlled variablelength usable for ablating, diagnostic sensing, or other desirableapplications.

It is therefore an object of the present disclosure to provide a familyof catheters with a flexible shaft and/or tip portion that can bendand/or deform and increase their contact area to tissue (and reversesuch bending or deformation via manual or robotic control input, forexample).

Another object of the present disclosure is to provide a catheter whoseablative length can be varied.

Yet another object of the present disclosure is to provide a catheterthat can be repeatedly reused and sterilized, within an engineereduse-limit, without harming the structural integrity of the catheter orendangering patients.

In one embodiment, a catheter includes an elongate body, a convolutedtip portion at a distal end of the elongate body, and at least onelumen. The convoluted tip portion includes an electroformed regular orirregular corrugated, creased, ridged, bellows-like or pleated region(herein in the plural form “pleated” or in the singular form “pleat”).The electroformed pleated region can have a tapered diameter along itslength or can be angled relative to the tip axis. The electroformedpleated region can include at least one fluid emission orifice which canbe laser drilled. The electroformed pleated region can be over coatedwith a noble metal or alloy or other biocompatible material. The pleatsprovide an improved bending or extensional behavior of the regionrelative to that of an equivalent unpleated region. Such pleats aretypically multiple in nature, with each pleat offering increasedflexural freedom such as for bending or axial compression/extension.

Pleats may also offer improved crush-resistance or kink-resistance.Pleats may be any designed undulation or shaping of the shell walls andcan be implemented by electroforming, which may favorably improvebending and/or extension behavior or avoid buckling behavior.

In another aspect, the convoluted tip portion and/or the elongate bodycan be hermetically sealed. In some embodiments the convoluted tipportion can include a non-round cross-section. Optionally, the elongatebody can include an acoustically transmissive window or a window for anoptical sensor.

In another embodiment of the present disclosure, the convoluted tipportion further includes one or more RF ablation elements. The RFablation element may be hermetically sealed and may or may not itself bepleated or formed out of electroformed material.

In yet another aspect of the present disclosure, a method ofmanufacturing a catheter includes the steps of forming an electroformedpleated region, obtaining a catheter shaft, and securing theelectroformed pleated region to the catheter shaft. The step of formingan electroformed pleated region further includes the steps of providinga mandrel having a pleated region, depositing (e.g., electroforming) ametal onto the mandrel, trimming the mandrel, and dissolving themandrel, thereby forming an electroformed pleated region. The step ofdepositing a metal onto the mandrel can include depositing anelectroformable metal such as nickel, copper or gold onto the mandrel.The method can further include the step of over coating theelectroformed pleated region (or, optionally, any unpleatedelectroformed region) with a gold, rhodium or platinum alloy.

In a further embodiment of the present disclosure, a tissue ablationsystem includes an RF ablation catheter having an elongate body, aconvoluted tip portion having an electroformed pleated region, and oneor more fluid chambers located adjacent to or within the electroformedpleated region. When the fluid chamber(s) is forcefully filled orforcefully evacuated, the fluid exerts a force to deform the convolutedtip portion. This hydraulic deformation can result in a useful bendingor change in length of the convoluted tip portion. In lieu of hydraulicactuation in certain embodiments, pneumatic actuation may be implemented(e.g., carbon dioxide gas or the like), with consideration given to thenature of the relevant medical applications or procedures.

In a further embodiment of the present disclosure, a tissue ablationsystem includes a catheter having an elongate body, a convoluted tipportion having an electroformed pleated region, and a mechanism fordeflecting the distal end of the elongate body. An example of amechanism for deflecting the distal end of the elongate body can be seengenerally by reference to U.S. application Ser. No. 11/023,667, filed 28Dec. 2004, now U.S. Pat. No. 7,691,095, owned by the common assignee ofthe present disclosure, and hereby incorporated by reference in itsentirety. Another technique for deflecting or steering a catheteraccording to the instant disclosure involves deployment of the cathetervia a deflectable introducer or sheath at least as to the majority ofshaft portion disposed within such an introducer (e.g., the AGILISintroducer designed, manufactured, and distributed by St. Jude Medical,Inc. of Little Canada, Minn.).

An advantage of the present disclosure is that it offers readilyreversible bending and extensional catheter tip and/or shaft flexibilitywhile also providing hermeticity or a sealed tip/body.

Another advantage of the present disclosure is that it provides amulti-length catheter tip whose ablative or sensing electrode length canbe varied in-vivo.

Yet another advantage of the present disclosure is that it provides acatheter having superb electrical shielding, kink-resistance, and torqueproperties.

A further advantage of the present disclosure is that it provides acatheter which can be repeatedly reused and sterilized, within theconstraints of a predefined number of safe uses, without affecting itshandling properties.

The foregoing and other aspects, features, details, utilities, andadvantages of the present invention will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a catheter having a convoluted tipportion according to an embodiment of the present disclosure.

FIG. 1A is a break-out view of an electroformed pleated region accordingto an embodiment of the present disclosure.

FIG. 2 illustrates a lengthwise extension of the convoluted tip portionaccording to an embodiment of the present disclosure.

FIG. 3 illustrates a convoluted tip portion according to an embodimentof the present disclosure bent or radiused against a tissue.

FIG. 4 illustrates an electroformed pleated region having laser-drilledorifices according to an embodiment of the present disclosure.

FIG. 5 depicts a convoluted tip portion having an angled pleated regionaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure provides a family of catheters having anelectroformed pleated region in the catheter tip portion that isdesirably and advantageously adapted to better conform to tissue andreduce perforations. The present disclosure also provides reusablecatheters wherein reuse is made possible by replacing conventionallyemployed polymeric lumen bodies with hermetic electroformed lumenbodies. The disclosure also provides a variety of methods ofmanufacturing a family of catheters with an electroformed pleated regionand a tissue ablation system utilizing a catheter with an electroformedpleated region.

Referring now to the drawings, and in particular to FIG. 1, a catheter10 includes an elongate body 100 having a convoluted tip portion 110with a length 180 at its distal end. Body 100 also defines a lumen 130(shown in phantom), which will be familiar to the ordinary artisan.

Lumen 130 can, for example, be configured to permit catheter 10 to beadvanced through a patient's vasculature over a guide wire.Alternatively, one or more steering wires (also commonly referred to aspull wires) can be routed through lumens such as 130. Lumen 130 can alsoprovide a passageway for electrical leads and/or signal wires. Lumen 130can also be adapted to receive one or more of an optical conduit, afluid, or a medical device. Such a fluid could be used for irrigation,tip-cooling, tissue cooling or even for hydraulic distortion of one ormore pleated regions such as a tip or an entire pleated catheter tipplus body. Of course, it should be understood that the present inventionis not limited to catheters having a single lumen 130, and that catheter10 can have multiple such lumens without departing from the spirit andscope of this disclosure. That is, in certain aspects, catheter 10includes multiple lumens, each of which may serve the same or adifferent purpose than one or more other lumens (e.g., multiple fluidlumens, one fluid lumen and one lumen for passing a medical device, andany other combination of lumens).

The catheter 10 can have axisymmetric or asymmetric handling properties.In general, catheter 10 can include one or more features that will befamiliar to those of ordinary skill in the art, such as embedded pullwires, braided reinforcing layers, and the like. Accordingly, theconstruction of catheter 10 will not be further described herein exceptto the extent necessary to understand the present disclosure.

In some aspects, the convoluted tip portion 110 may be a mating partsecured, for example by an adhesive or a snap-fit connection, toelongate body 100. Alternatively, the convoluted tip portion 110 may beintegrally formed with elongate body 100 such that the entire extendedcatheter 10, including the elongate body 100, convoluted tip portion110, and length 180, is all electroformed. Although known push/pull ortwisting control wires may be used to distort one or more pleatedregions of the inventive catheters, for example a pleated tip or afull-length pleated catheter, the inventors also anticipate the use ofliquid hydraulics or pneumatic gas pressure as applied through one ormore pressurization lumens to distort the catheter tip and/or body.Specifically, in one preferred embodiment, the pleated catheter portionenwraps a polymeric-based multilumen tube. The interior flexiblemultilumen tube has multiple isolated fluid passages off of its centralaxis such that pressurization of an outboard lumen causesstretching/compression or bending of a pleated catheter section. Theinterior multilumen tube can also be employed as a nondisposableincorporated mandrel for use in electroforming portions of catheter 10as disclosed herein. For example, the polymeric multilumen tube may berendered plateable, such as by placement of a sputtered/ion-depositedmetal film or an electroless nickel plate “seed” coating. The multilumentube mandrel can then be left in the electroform permanently, ratherthan dissolving it as described herein.

In other aspects the convoluted tip portion 110 can provide a windowregion for a sensor or other device disposed within tip 110 or routedthrough lumen 130. For example, an optical sensor may be disposed withintip 110, and an optically-transparent window can be provided tofacilitate use thereof. Similarly, the convoluted tip portion 110 caninclude an acoustic window, which permits the transmission of acousticenergy from an acoustic (e.g., ultrasound) transducer disposed withintip 110 and oriented to emit and receive acoustic energy through theacoustic window. One of ordinary skill would readily appreciate how suchsensors and other devices may be installed or otherwise disposed in tip110 or routed through or passed through lumen 130. Ceramic or glasswindows for allowing such ingoing/outgoing sensor energies may be brazedor soldered into the electroformed shell thus preserving absolutehermeticity.

The convoluted tip portion 110 includes an electroformed pleated region120. The electroformed pleated region 120 can have an overall averagevarying shape, such as straight and cylindrical, tapered or of steppeddiameter along its length. Alternately, the electroformed pleated region120 can have a constant average diameter along its length. In anotheraspect, the electroformed pleated region 120 can have a cross-sectionwhich is, at least in part, nonround such as polygonal or oval. Thepleated region provides bendability and/or extendability in one or moredirections. Such motions may be employed, for example, in gainingimproved access through vasculature, in placing the catheter tip in amore beneficial tissue-contact state, or even for cyclically scanningthe tip such as to achieve a scanning motion for a sensor or imagingtransducer in the tip.

Electroforming upon a shaped sacrificial mandrel, sometimes alsoreferred to as electrodeposition, which is described further below,allows pleated region 120 to offer numerous advantages. For example,electroformed pleated region 120 can act as an adjustable-lengthelectrical conductor for a useful medical purpose, such as for use as avariable-length ablation electrode or electrode for sensing electricalactivity (e.g., cardiac electrograms) or for pacing the heart. Ofcourse, electroformed pleated region 120 offers other advantages aswell. For example, electroformed pleated region 120 can provide safetyadvantages such as bendability, extendability, and compressibility toavoid tissue perforations while at the same time encouraging intimatetissue contact. The electroformed pleated region 120 also providesimproved crush-resistance and kink/buckling resistance. Likewise,electroformed pleated region 120 can provide electromagnetic shieldingagainst interference for incoming and/or outgoing signals. Additionally,if electroformed pleated region 120 includes nickel deposits, it couldbe manipulated utilizing magnetic steering systems, such as the NiobeRemote Magnetic Navigation System from Stereotaxis, Inc. of St. Louis,Mo. or the magnetically-controlled catheter systems of MagnetecsCorporation of Los Angeles, Calif.

The electroformed pleated region 120 is formed by a plurality ofindividual pleats 170. These pleats 170 can be integrally formed, or,alternatively, can be formed as a plurality of segments that aremetallurgically joined (e.g., by laser welding). A break-out view ofelectroformed pleated region showing individual pleats 170 with athickness 240 is depicted in FIG. 1A. A thickness 240 of theelectroformed pleats may for example be in the range of about 0.001 toabout 0.006 inches. In one preferred embodiment, the electroformedpleated region 120 is fabricated by electroforming all of the pleats asa pleated body on a common mandrel wherein no individual pleat-joiningis then later required.

The individual pleats 170 can be arranged at angles to each other, whichcan desirably impart direction-biased bending and extensional capabilityto electroformed pleated region 120. Pleats 170 also advantageouslyincrease the radiopacity of the convoluted tip portion 110.Additionally, the individual pleats 170 desirably increase theresistance of electroformed pleated region 120 to buckling and/orcollapse in comparison to a non-pleated electroformed structure. Anotheradvantage is that individual pleats 170 act to provide a favorablecontact impedance or resistance to tissue by assuring multiple parallelelectrical contacts to tissue. Still another advantage is that theindividual pleats 170 atraumatically enhance tissue gripping, whilebeing shaped to minimize the likelihood of pinching or grabbing tissuerelative to certain extant devices. One of skill in the art wouldrecognize the pleated tips of the invention as corrugated (pleated)thin-walled shell structures whose respective pleats or corrugations canhave varying size, shape, depth, pattern, thickness, and number thatessentially determine the overall bendability, extendability, kinkresistance, crush resistance and torqueability of the overall structureand portions thereof in conjunction with any of a variety of deflectionschemes including mechanical, hydraulic, pneumatic and the like.

One suitable method of forming electroformed pleated region 120 is asfollows. First, a sacrificial mandrel having a pleated region isprovided. Next, an electroformable metal is deposited (e.g.,electroformed from a chemical bath) onto the mandrel. One known suitableelectroformable metal is electrodeposited nickel. One of skill in theart will appreciate that the wall thickness 240 of the electroformedpleated region 120 is determined by the thickness or amount of depositedelectroformed metal. Once the metal has been deposited onto the mandrel,the mandrel is typically trimmed and dissolved. In the case ofelectrodeposited or electroformed nickel, a dissolvable preshaped(pleated) aluminum mandrel may be sacrificed. Aluminum mandrels areconvenient because they can be easily shaped and easily dissolved, andthey are electrically conductive for electroforming thereon. If amaterial other than a metal is employed for the mandrel (note themultilumen polymeric mandrel example described above) then it must berendered at least surface conductive first as by a deposited metalthinfilm or electroless plated thinfilm metal. Then the thinly metalcoated polymeric mandrel can be electroformed upon. A polymeric mandrelcan be extruded or even molded with a variety of favorable undulating orpleated shapes. As described above, such a polymeric mandrel can remainin the electroformed catheter as an integral design element and canitself be formed, molded or extruded to have the desired pleated shape.The mandrel may take any of a plurality of shapes, which can be selectedaccording to the intended or desired use of the resulting electroformedpleated region. Optionally, the electroformed pleated region 120 can beover coated with a noble metal or alloy such as gold or a gold alloy, orplatinum or a platinum alloy for biocompatibility or enhancedtissue-contact properties. Electroforming techniques such as thosedescribed by Precision Manufacturing Group, LLC in relation to itsServometer® division product and service offerings can also be used inconnection with the present disclosure.

The electroformed pleated region 120 can be hermetically sealed ifdesired since the electroformed metal shell is itself inherentlyhermetic, in contrast to polymer materials often used in catheterconstruction. In another aspect, the elongate body 100 or the entirecatheter 10 can be hermetically sealed, such as by forming it all out ofelectroformed (e.g. nickel) material without any joining metal/polymerseams. If a seam or joint is necessary it can be a metal/ceramic/metaljoint which is soldered for example. Hermetic sealing permits thecatheter 10 to be sterilized without damage such as by wet methods,gaseous (ETO) methods or even steam autoclaving. This offers anadvantage over the prior art, for example because polymeric materialsoften admit some liquid and/or gaseous sterilant via bulk diffusion. Theliquid and/or gaseous sterilant attacks features of the catheterinterior such as conductor wires, which may result in degradation of thepolymeric shaft and/or lumen construction materials themselves. Gammasterilization would also be more benign if the catheter is fabricated ofelectroformed metal rather than of polymers susceptible to gammaembrittlement. Hermetic sealing of the catheter also prevents internalwater deposits due to condensation from sterilization procedures such assteam autoclaving. The ability of catheter 10 to undergo sterilization(e.g., autoclaving, wet immersion sterilization, plasma sterilization)without damage or degradation is particularly desirable, insofar asextant polymeric catheters can degrade after even a single sterilizationcycle.

Thus, catheter 10 according to the instant disclosure can be labeled fora specified engineered safe number of multiple uses, or, alternatively,can have enforced disposability after a specified number of safeengineered multiple uses, making catheter 10 a more economical choicefor practitioners. “Enforced disposability” means that the cathetercannot safely be used after a certain number of uses, and may beprovided in any suitable fashion. In certain aspects, enforceddisposability is provided by including an integrated circuit (“IC”)chip, such as in the handle or connector, that stores and reports (e.g.,to other components of a tissue ablation system) how many times catheter10 has been used and allows such use up to a preset number of uses(e.g., by preventing the tissue ablation system from activating if thepreset number of uses has been exceeded). Of course, catheter 10 canalso be disposable or disposed of after a single use without departingfrom the present teachings.

FIG. 2 illustrates a lengthwise (stretched) extension of the convolutedtip portion 110 of FIG. 1 according to an embodiment of the presentdisclosure. As depicted in FIG. 2, the convoluted tip portion 110 can beextended to a length 190 that is greater in length than the undisturbed(e.g., as-electroformed) length 180. Similarly, in another aspect,convoluted tip portion 110 can be shortened (e.g., compressed) to alength 200 that is shorter in length than the undisturbed length 180 asby applying a negative pressure (suction) to a liquid filledelectroformed tip fluid chamber. Advantageously, the catheter 10 can beadvanced or retracted from a lumen or blood chamber by using thislengthwise deformability of the tip or of the tip/lumen body. As the tiplength 200 is compressed or stretched, the pleats are forced closertogether or further apart, with each pleat acting like a small spring.

The extension or contraction in length of convoluted tip portion 110described above can be effected in any suitable manner. For example, insome embodiments, internal fluid pressure is used to effect the changein length. That is, a positive pressure can be created in a fluidchamber 250 located adjacent to or in the electroformed pleated region120 (e.g., by filling fluid chamber 250 with a pressurized fluid, suchas saline) to extend the length of convoluted tip portion 110, while anegative pressure can be created in fluid chamber 250 (e.g., byevacuating (applying suction negative pressure to) fluid chamber 250) tocontract the length of convoluted tip portion 110. Examples of fluidsmay be liquids such as saline or gases such as biocompatible carbondioxide. As previously noted, by providing multiple off-axispressurization lumens one could, by selective or differentialpressurization, achieve bending of a pleated section. Some electroformedshapes will also encourage deformation along a direction or axis ofleast elastic resistance such as via a rotational torque deformation.

In other aspects of the disclosure, the lengthwise extension orcontraction of convoluted tip portion can be caused by contact withtissue, an internal spring or wire, or by a user pushing, pulling,twisting, or otherwise manipulating the catheter. In one aspect theconvoluted tip portion 110 bends as it comes into contact with tissue.The bending of convoluted tip portion 110 causes part of the convolutedtip portion 110 to extend while causing another opposed portion of theconvoluted tip portion 110 to contract. One of ordinary skill in the artwould appreciate that the pleats or corrugations may have differentsizes, arrangements and distributions depending on the catheterdistortions and/or flexibility desired. In general the electroformedmetal thickness 240 is small in comparison to the dimensions of thepleats (pitch, height, radius, etc.) themselves. Pleats for promotingbending and stretching may be of any shape which encourage deformationat reduced loading (i.e. makes the part more easily deformable than theunpleated electroformed form). Pleats could, for example, be generallytriangular, radiused, round, polygonal, square or rectangular. They maybe stacked and independent of each other or they may be continuous inthe case of their being screw-thread or helical in shape. They may occurin groups or even singly. They may have various orientations to thelocal catheter/lumen central axis. Their spacing, shape and/or size maysystematically vary with distance or position on the electroform. Theirstiffness behavior may be modeled using 3D CAD programs or simulators.

FIG. 3 illustrates that the convoluted tip portion 110 can further actas or physically include one or more RF ablation elements. Likewise, theelongate body 100 can include a catheter control handle at its proximalend (not shown). Advantageously, the adjustable length of the RFablation element in FIG. 3 comprises all of pleated section 120. Thus,the catheter 10 can be readily used for sensing, mapping, pacing, orablating. Moreover, the variability of the length of RF ablation elementand its bending flexibility desirably permit long and continuous curvedor straight lesions.

In one embodiment of the invention, the insulating spacer 140 of FIG. 3is a ceramic spacer which electrically isolates the pleated electrodetip 110 from the rest of the pleated catheter shaft 100. This allows forablation only from the tip portion. The insulating spacer 140 caninclude an alumina cylinder having through-holes or lumens for wiringand having selectively-placed external metallization for solder joiningto the adjacent electroformed tip 110 and shaft 100. An electroformedflexible tip can have both superior bendability and tissue-conformancebut also have its ablative-length changeable as by the aforementionedpressurizations. Note that the entire catheter of FIG. 3 is inherentlyhermetic and sealed.

FIG. 3 also illustrates a convoluted tip portion 110 according to anembodiment of the present disclosure that is bent or radiused against aheart or myocardial tissue 210. The bending of the convoluted tipportion 110 can be effectuated in any suitable manner, including theways described above with respect to lengthwise extension or contractionof convoluted tip portion 110. The bending of the convoluted tip portion110 offers numerous advantages, including better contact with tissue andless likelihood of tissue perforations, enhanced antisliding resistance,reduced electrical impedance, and superior heat removal. Elongate body100 can also be bendable (or even extendable) as depicted by its ownsmaller pleats as shown. In one aspect the tip 110 is bendable by theforces imposed on it by when brought into contact with tissue.Bendability of the tip 110 (or even of an electroformed body-lumen) canbe achieved through mechanisms such as pull wires or thepressurization/differential pressurization of off-axis fluid lumens.Lumens employed for fluidic or pneumatic pressurization to achievefavorable electroform distortion may or may not be independent of anyemployed for cooling or irrigation.

The pleated shaft 100 as illustrated in FIG. 3 may have a pleat pitch ofabout 2.5 mm, with a large pitch to height ratio. A greater pitch toheight ratio provides for a structurally stiffer catheter shaft 100,i.e. one that is flexible but can be maneuvered by pushing and pulling.One of ordinary skill in the art would appreciate that by varying thepleat shapes and dimensions along the tip/shaft that any desiredstiffness requirement can be met without changing the tip/shaftmaterial. This allows, for example, the creation of preferred stiffnessprofile catheter products for specific customers.

Typically the electrodeposited or electroformed metal thickness will bea few mils or thousandths of an inch. For example, typical thicknesseswould be between 1 mil (0.001 inch or 25.4 microns) and 7 mils (0.007inch or about 178 microns). The pleat pitch and pleat height wouldtypically be significantly larger as shown in the figures—thus providinga thin-walled or shell-like pleated object whose flexure behavior isdominated by the “thin flexible” pleats. Pleat pitches and heights willcommonly be many times the electrodeposit thickness, e.g., 2-20× andprobably more commonly 4-8×.

FIG. 4 illustrates a tissue ablation system according to an embodimentof the present disclosure. A catheter includes a convoluted tip portion110 having an average diameter 230. The convoluted tip portion 110comprises an electroformed pleated region 120, an RF ablation element,and fluid emission orifices 220. The electroformed pleated region 120includes individual pleats 170 with an axial pitch 260, a total radialheight 270, a thickness 240, and an average diameter 230. Axial pitch260 and radial height 270 can be optimized so that desired flexibility,stiffness, torque transmission, and extensional properties can beachieved. One of skill in the art will appreciate that the bending,torque, and extensional properties of the electroformed pleated region120 (or the more mildly pleated shaft 100 of FIG. 3) will be determinedlargely by the ratio of axial pitch 260 to radial height 270, the numberof individual pleats 170, and the ratio of radial height 270 to diameter230, or the ratio of radial height 270/diameter 230 and thickness 240.

In one aspect, the individual pleats 170 vary in shape, size, and/orconfiguration along the length of the electroformed pleated region 120to provide variations in certain properties of catheter 10 (e.g.,increased flexibility of the catheter). For example, each individualpleat 170 can comprise an axial pitch 260 and a radial height 270 thatcan be the same or different from other individual pleats 170. Thepleats 170 may be joined by corners having controlled radii as shown inthe Figures. Pleats 170 may have one of a plurality of shapes such asthe illustrated sawtooth or sine wave, round ribs, etc. Additionally,the pleats 170 may be singly stacked as shown or may form continuous ordiscontinuous spirals and the like.

In one embodiment of the invention, the electroformed thickness 240 perthe above comments on thickness will typically be significantly lessthan a pleat pitch, width or height such that a flexible membrane isprovided which can be treated as a curvilinear or corrugated elasticshell. In a preferred embodiment, the thickness 240 will be in the rangeof about 0.001 to about 0.007 inches such that local portions areelastic and easily bendable. The pleat pitch and height will be largerthan the thickness 240 and preferably of the same order of magnitude aseach other (e.g. both within the above 4-8× ratio range for example).For example, a specific ablation tip may have an electroformed thicknessof about 2 mils (0.002 inch or about 50 microns), a pleat pitch of 12mils (0.012 inch or about 305 microns) and a pleat height of 10 mils(0.010 inch or about 254 microns) and an average tip diameter of 8French or 8/Pi=2.548 mm or about 2548 microns. In such embodiments, thetip has pleat features which occupy about (254×2)/2548 or 0.20 or 20% ofthe average diameter as roughly shown in FIGS. 1 and 2.

Irrigant fluid emission orifices 220 shown in FIG. 4 can be laserdrilled. Laser drilling is particularly advantageous, as the laserdrilled holes can be drilled anywhere in the electroformed pleatedregion 120 and can thus jet fluid in almost any direction since pleatfaces may be directed in numerous directions. Alternately, the fluidemission orifices can have their flow directed radial to the catheter 10or convoluted tip portion 110 axis. In yet another embodiment, the fluidemission orifices can have their flow directed at an angle to thecatheter 10 or convoluted tip portion 110 axis. In another embodiment,the shaft 100 comprises saline lumens running up and down the shaft 100that provide a closed, circulating cooling scheme. In yet anotherembodiment of the invention, the irrigant is expelled from the shaft100.

FIG. 5 depicts a convoluted tip portion 110 having an electroformedpleated region 120 according to an embodiment of the present disclosure.In this embodiment, the electroformed pleated region 120 comprisesindividual pleats 170 that are angled relative to the tip axis 280.These may form a spiral or simply a stack of tilted yet parallel pleats(shown). Thus, upon fluid pressurization or wire-push extension, theconvoluted tip portion 110 extends in an angled direction 290 Additionalsculpturing or hole-drilling of the inventive tips as by laser cuttingof electro-discharge machine (“EDM”) is yet another embodiment of theinvention.

Although several embodiments of this disclosure have been describedabove with a certain degree of particularity, those skilled in the artcould make numerous alterations to the disclosed embodiments withoutdeparting from the spirit or scope of this invention. For example,though the disclosure describes only a single electroformed pleatedregion 120, one of ordinary skill in the art can envision that acatheter 10 could comprise more than one electroformed pleated region120 in a tip. For instance, the catheter 10 could comprise a firsthighly flexible pleated region 120 in the tip and a second, lessflexible pleated region 120 in (or as) the catheter body.

As another example, a person of skill in the art could incorporatemultiple sensors, electrodes, and/or transducers in the catheter body tobetter visualize or ascertain the content or behavior of various tissuestructures. Likewise, one or more catheter tracking elements can becoupled to or formed within a portion of a catheter so that a systememploying non-ionizing radiation can be used to locate the catheterduring a procedure or working condition. Examples of such systemsinclude the EnSite System from St. Jude Medical, Inc. of Little Canada,Minn. and the CARTO system from Biosense Webster, Inc. of Diamond Bar,Calif. These systems utilize either catheter tip electric fieldpositioning (former) or catheter tip magnetic field positioning(latter). As still another example, one of ordinary skill in the artwill appreciate that a metallic or pleated convoluted shaft also hassuperb electrical shielding properties such as for high-sensitivitywaveform detection. This is true even in unpleated yet electroformedregions.

In some embodiments, the catheter tip is disposable, but thelumen/body/handle component is not disposable, i.e. they are separableby a connector or coupling. Such could be achieved by having apositive-locking sealing connector between disposable and nondisposablesections. Alternatively, the tip may be reuseable, the lumen/body/handlemay be disposable, and at least one of the tip and/or lumen/body areelectroformed and pleated.

The invention may be used to provide individual practitioners withindividually customized catheter behaviors such as by using customelectrodeposition mandrels for each doctor. These catheters may bedisposable or controlled-reuseable depending on design and cost.

The novel use of a polymeric extrusion or polymeric molded entity as anelectroforming mandrel has been described above. In such embodiments,such as where the entity has lumens, the polymeric “mandrel” maypermanently remain a part of the catheter thereby avoiding thetraditional electroforming step of dissolving the mandrel. In suchcases, the electroformed shell is permanently bonded to the polymericliner (mandrel), because electroforming was done on a thin-filmmetalized polymer mandrel. The mechanical properties of the catheter maybe varied both by changing electroformed dimensions/shapes but also bychanging polymer dimensions/shapes and even materials. Such a polymericcore might also be a highly deformable foamed material such as aclosed-cell foam.

All directional references (e.g., upper, lower, upward, downward, left,right, leftward, rightward, top, bottom, above, below, vertical,horizontal, clockwise, and counterclockwise) are only used foridentification purposes to aid the reader's understanding of the presentinvention, and do not create limitations, particularly as to theposition, orientation, or use of the invention. Joinder references(e.g., attached, coupled, connected, and the like) are to be construedbroadly and may include intermediate members between a connection ofelements and relative movement between elements. As such, joinderreferences do not necessarily infer that two elements are directlyconnected and in fixed relation to each other.

It is intended that all matter contained in the above description orshown in the accompanying drawings shall be interpreted as illustrativeonly and not limiting. Changes in detail or structure may be madewithout departing from the spirit of the invention as defined in theappended claims.

What is claimed is:
 1. A device comprising: an elongate body, whereinthe elongate body has a longitudinal axis; a variable length tip portionat a distal end of the elongate body, wherein the variable length tipportion comprises a first elastically deformable electroformed pleatedregion and the elongate body comprises a second elastically deformableelectroformed pleated region, wherein the first and second elasticallydeformable electroformed pleated regions comprise adjacent pleats thatextend perpendicularly to the longitudinal axis, such that the first andsecond elastically deformable electroformed pleated regions expandaxially, and further wherein the first and second elastically deformableelectroformed pleated regions are capable of being extended to a lengththat is greater than the undisturbed length; and at least one lumen;wherein the first elastically deformable electroformed pleated regionfurther comprises at least one ablation element, and wherein the firstelastically deformable electroformed pleated region in the variablelength tip portion is more flexible than the second elasticallydeformable electroformed pleated region in the elongate body.
 2. Thedevice according to claim 1, wherein the first elastically deformableelectroformed pleated region further comprises at least one fluidemission orifice.
 3. The device according to claim 2, wherein the atleast one fluid emission orifice is laser drilled or electro-dischargemachined.
 4. The device according to claim 1, wherein the first and/orsecond elastically deformable electroformed pleated region is capable ofextension by internal pressure.
 5. The device according to claim 1wherein the at least one ablation element is a radiofrequency (RF)ablation element, and the RF ablation element is hermetically sealed. 6.The device according to claim 1, wherein the first and/or secondelastically deformable electroformed pleated region has a tapereddiameter along its longitudinal axis.
 7. The device according to claim1, wherein at least one of the adjacent pleats of the first or secondelectrically deformable electroformed pleated regions is oriented at anangle between 0 and 90 degrees to the longitudinal axis of the tipportion.
 8. The device according to claim 1, wherein the firstelastically deformable electroformed pleated region further comprises anon-round cross-section.
 9. The device according to claim 1, wherein theelongate body further comprises at least one fluid lumen.
 10. The deviceaccording to claim 9, wherein the elongate body further comprises atleast one fluid emission orifice.
 11. A deformable device, comprising: aradiofrequency (RF) ablation catheter having an elongate body comprisinga first elastically deformable electroformed pleated region and anelastically deformable convoluted tip portion, wherein the elasticallydeformable convoluted tip portion comprises a second electroformedpleated region, wherein the first and second elastically deformableelectroformed pleated regions comprise adjacent pleats; a fluid chamberadjacent to the second electroformed pleated region, wherein, the fluidchamber is capable of being pressurized with a fluid, and furtherwherein the fluid is capable of deforming the elastically deformableconvoluted tip portion; and wherein the second elastically deformableelectroformed pleated region is more flexible than the first elasticallydeformable electroformed pleated region.
 12. The device according toclaim 11, wherein the deformation is configured to result in a bendingof the elastically deformable convoluted tip portion.
 13. The deviceaccording to claim 11, wherein the deformation is configured to resultin a change in length of the elastically deformable convoluted tipportion.
 14. A device designed for multiple uses and sterilizations upto a preset limit, comprising: an elongate body, wherein the elongatebody comprises a distal end and a proximal end, wherein the distal endcomprises a distal tip connected to the elongate body, and furtherwherein the distal tip comprises a first flexible convolutedelectroformed metal shell and the elongate body comprises a secondflexible convoluted electroformed metal shell, wherein the first andsecond flexible convoluted electroformed shells are substantiallyhermetic; a control handle located at the proximal end of the elongatebody for manipulating the device; wherein the device is operablyconnected to an integrated circuit chip configured to determine thenumber of past uses already consumed and permits further usages up tosaid preset limit; and wherein the first flexible convolutedelectroformed metal shell is more flexible than the second flexibleconvoluted electroformed metal shell.